Saturday

December 20, 2014

December 20, 2014

Posted by **Larry English** on Friday, September 9, 2011 at 9:10pm.

a) Approximately 68% of the grades were between which grade?

b) Approximately what percentage of grades were between 55 and 76?

- Statistics -
**PsyDAG**, Saturday, September 10, 2011 at 1:34pma. 68% are mean ± 1 SD.

b. Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores (from Z = -2 to +1).

**Answer this Question**

**Related Questions**

Quantitative methods - the mean and standard deviation of the grades of 500 ...

Quantitative methods - the mean and standard deviation of the grades of 500 ...

statistics - If the grades on a police entrance exam are normally distributed ...

statistics - Percentage grades in a large physics class follow a normal ...

Statistics - Exam Grades. A statistics professor is used to having a variance in...

college - Suppose that, for a certain exam, a teacher grades on a curve. It is ...

statistics - In a large class, there were 220 students who wrote both the ...

statistics - In one history class, 34 students took an exam. The mean of the ...

statistics - 2. The grades on a statistics midterm exam were normally ...

Algebra II - The grades on the last math exam had a mean of 88%. Assume the ...